In general, this invention relates to methods of producing nonwoven fibrous panels having a textured outer surface as well as fibrous panels produced by such methods. More particularly, this invention relates to a method for producing a nonwoven fibrous, flexible panel having a textured outer surface that includes needlepunching a needled web of at least interengaged first fibers and second thermoplastic fibers to produce the textured outer surface; and passing a fluid, at a temperature sufficient to melt at least a portion of the second thermoplastic fibers, through the web in a direction from the textured outer surface to produce a plurality of weld joints of the melted fibers; and it relates to nonwoven fibrous panels produced by such methods.
At present, nonwoven fabric interior linings and floor mats for motor vehicles made up of nonwoven fabrics having tufted surfaces to which a sintered thermoplastic, latex, latex compound, or flexible urethane resin layer must be applied to prevent fraying and to secure the tufts in place, are known such as those disclosed in: Wishman (U.S. Pat. No. 4,320,167); the FIG. 6 embodiment of Benedyk (U.S. Pat. No. 4,258,094); Walters et al. (U.S. Pat. No. 4,581,272); DiGioia et al. (U.S. Pat. No. 4,016,318); Hartmann et al. (U.S. Pat. No. 4,169,176); Sinclair et al. (U.S. Pat. No. 4,186,230); Zuckerman et al. (U.S. Pat. No. 4,242,395); Morris (U.S. Pat. No. 4,230,755); Robinson (U.S. Pat. No. 3,953,632); Pole et al. (U.S. Pat. No. 4,199,634); and FIG. 3 of Miyagawa et al. (U.S. Pat. No. 4,298,643). Applying such a layer to the nonwoven fabric substantially increases the cost to produce the interior linings and floor mats due to added costs of (1) using, storing, and properly applying the sintered thermoplastic, latex, latex compound, or urethane layer, and (2) the complex manufacturing machinery and added labor required to apply such a layer. Tufting is the drawing of yarns through a fabric, either woven or nonwoven, using a tufting machine. Tufting machines are generally multineedle sewing machines which push the yarns through a primary backing fabric that holds the yarns in place to form loops as the needles are withdrawn. Tufting requires that yarns separate from the woven or nonwoven backing fabric be used to form the tufts; thus, tufting of nonwoven fabrics to produce interior linings and floor mats adds costs to manufacture such items.
Related patents, each of which discloses a specifically-described nonwoven fabric heated in a particular manner, are as follows: Street (U.S. Pat. No. 4,668,562); Sheard et al. (U.S. Pat. No. 4,195,112); Benedyk (as above '094); Erickson (U.S. Pat. No. 4,342,813); Newton et al. (U.S. Pat. No. 4,324,752); Mason et al. (U.S. Pat. No. 4,315,965); and Trask et al. (U.S. Pat. No. 4,780,359). In particular, the nonwoven staple polymer fiber batt of Street (as above '562), also known as a high-loft nonwoven fabric, is simultaneously compressed substantially by vacuum and heated by pulling air at a temperature that will only make the polyester soft and tacky, through the batt. FIGS. 2 and 9 of Street ('562) illustrate the change in thickness and density of the batt before and after the disclosed Street process has been performed on the batt. Such substantial batt compression is undesirable in the fabrication of nonwoven fabric interior linings and floor mats, or the like, which generally have a decorative outer surface and must have sufficient strength and thickness to withstand frequent and harsh use.
It is a primary object of this invention to provide a method for producing a nonwoven fibrous, flexible panel retaining a "velour-like" textured outer surface, which is capable of withstanding frequent and harsh use without necessarily needing a backing layer of sintered thermoplastic, latex, latex compound, urethane, or the like. It is another object to produce a nonwoven fibrous panel by such a method that is less costly to make or has fewer different requisite components than known nonwoven fabric products of similar nature.